Improved arrangement of vertical-tube feed-water heaters in locomotive smoke-stacks



UNITED STATES PATENT GEEICE v MArrHIAsw. BALDWIN AND DAvID CLARK, or PHILADELPHIA,

PENNSYLVANIA. y

IMPROVED ARRANGEMENT OF VERTICAL-TUBE FEED-WATER HEATERS` IN LOCOMOTIVE SMOKE-STACKS.

Specification forming part of Letters Patent No. 10,5i4, dated February 14, 1854.

To all whom it may concern.-

Be it known that we, MATTHIAS lV. BALD- WIN, of the citv and county of Philadelphia, State of Pennsylvania, and DAVID CLARK, now of Philadelphia, late of count-yvof Schuylkill, (State of'Pennsylvania,) have invented certain ne-w and useful improvements in the method of heating feed-water for steam-boilers by the Waste heat of the exhaust-steam and spent gases as they pass to the chimney, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, making part of this specification, in which- Figure l represents a vertical. transverse section through the chimney and smoke-box of a locomotive-boiler furnished with our improvement; Fig. 2, a perspective view of the outside of chimney and boiler.

Various attempts have been heretofore made to heat the feed-Water for steam-boilers by the heat of the smoke, gases, and steam which escape through the pipe; but none of them have been hitherto found practically available. In every instance the injury to the draft of the furnace has been greater than the beneficial effect in heating feed-water. One mode proposed consisted of a water-chainber placed on the lower part of the pipe and furnished with numerous vertical tubular passages open above and below, through which the steam-jet and smoke and gases discharged. rlhe feed-water circulated through this lower vessel in its way to the boiler and was thereby heated. These tubular passages were small and of uniform sections. The steam-jet discharged just below their lower extremities and its force was distributed through them.

In practice it was found that the draft of the locomotive was injured, and in our opinion this was owing to the relative position of the steam-jet and the tubular passages and the uniformity and smallness of these tubular passages, the draft due to the steam-jet not being developed, and the steam condensing on the sides of these small tubes caused them to become' coated with ashes. The saine method was again tried with a series of vertical annular passages substituted for the tubular passages. The same arrangement of the steam-jet and proportion of parts was observed, and the saine results followed. A

third method was tried, in which a vertical tubular passage of larger diameter was placed immediately over the steam-jet and a double curved or /N formed smoke and gas passage surrounded this central passage. This curved passage commenced in the upper part of the smoke-box, passed up to the top of the heater and then down again, and, finally, terminated in the lower part of the central tubular passage. The draft by this arrangement was found to be no greater than that due to the central tubular passage alone without the curved passages, and this was insuiiicient.

Our arrangement is an improvement on the three foregoing plans, and we have found in practice that it attains the useful result aimed at therein without injuring the draft of the locomotive-furnace.

Our improvement consists in constructing the heater with a central vertical tubular passage of such a proportionate section and height as will permit the development of the force of the draft due to the first impact of steam, and so that the steam may, after passing the upper extremity of the central tube, expand to the full section of the chimuey. Around this central passage just mentioned a series of vertical tubular passages .are placed of small section. These open below into the smokebox and above into the main chimney at the same height above the smokeboxy that the central vertical passage opens.

ln the accompanying drawings, Fig. lrepreseuts a section of our improved arrangement attached to a locomotive-boiler. A represents the heater, which is an upright cylindrical vessel having a central tubular passage b of large section and surrounded by a series of tubular passages c c of smaller section. a n represent the blast-pipes entering the smoke-box in the usual manner and terminating in nozzles at 0 o, immediately below the center of the tube or pipe b. The water is forced into the heater through pipes enter` ing its sides at L', Fig. 2, by force-pumps, in the usual manner, and passes out at the Vtop of the heater to the boiler through a pipe m.

Locomotive-engines vary in their construction, according as they are intended to run at high or at low velocities, or lwith heavy or light trains, or to use steam at various degrees of expansion. These conditions materially affect the force of the blast required and the amount of water required to be heated. AHence it will be seen that the same proportion of parts will not suit all locomotives, and we desire not to confine ourselvesto any precise or specific dimensions, but to use those which, in accordance with the principle of construct-ion hereinafter mentioned, are best adapted to the machine to which the heater is to be attached. The following proportions have been found to answer well. Foralocomotive having a cylinder fourteen inches diameter we malte the central tube seven in ches diameter and place thirty-two tubes of one and seven-eighths inch diameter each around it. The vertical length of each of these tubes is about twenty-four inches. Fora sectional area of central tube one-fourth of that of the cylinder the surrounding tubes are about two inches diameter and of sufficient number to give an. area of about fifty-seven one-hundredths of the area of the cylinder-that is, presuming the relative proportion of cylinder and fire-surface to have been correctly 0bserved in the construction of the locomotive to which the heater may be attached. The nozzles at O are placed immediately below the center of b, so that the whole of the steamjet must pass into and through the tube b. The tubes c c e are open below intoihe smokebox and above into the lower end of the main chimney at E.

The operation ofthe apparatus is as follows: The steam enters from the nozzles below the lower extremity of the tube b. It expands until it reaches the circumference of b, and then acts by its `propulsive force to drive the air before it through the tube b. The vacuum thus produced creates a draft through the tube b from the smoke-box. lVhen the steam from the jets reaches the upper extremity of b, it expands until it reaches the circumference of the main pipe at E, and then acts by its propulsive force on this increased section and drives an additional quantity o f air before it, creating a further draft. The draft thus created is supplied through the tubular passages c c e e, which open into the main pipe just at the point where the steam expands to fill the main chimney. The prin ciple of our improved arrangement will thus be seen to be the employment of the expansive capacity of the steam from the jet by adapting thereto the height and relative sec,

tion of the central tubular space and the rendering of the auxiliary draft thus obtained operative through the medium of a series of surrounding tubular passages opening directly from the smoke-box into the lower part of the main smoke-pipe. The Whole of the exhaust steam passes through the central tube b and is followed by a portion of the smoke and gases, which thus communicate a portion of their heat to the feed-water; but the surface of this tube is not suiiicient to condense the steam, and the jet leaves the upper end of the tube and enters the smokepipe with the same or nearly the same power to produce the vacuum as though the heater were not used. The vacuum produced in the smoke-pipe by the exhaust-steam draws the greater portion of heated air, gases, &c., through the small tubes of the heater, and as there is no steam in contact with their inner surfaces there is nothing to cause the ashes to adhere to their surfaces. We have found by nu merous practical trials that-this arrange ment of large central tube, steam-jet, and

smaller surrounding tubes open above and below does not injure the draft of the locomotive in the least. At the same time no incrustation takes place on the inner surface of the tubes. Thus the difliculties experienced in the plans referred to in the first part of this specification are obviated and a practical method of heating the feed-water of locomotives is attained.

Having thus described our improvement, we do not desire to claim as our invention the employment of a heater for feed-water containing vertical tubular passages; but

What we do desire to claim and secure by Letters Patent is The arrangement of the exhaust-pipes with a vertical central passage of large section and surrounding passages of smaller section, said central pipe and smaller passages being open above and below, in the manner and for the purpose substantially as hereinbefore described.

M w. BALDWIN. DAVID CLARK.

Witnesses:

HENRY SIMPSON, GEORGE HARDING. 

